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authorSimon Rettberg2026-01-28 12:53:53 +0100
committerSimon Rettberg2026-01-28 12:53:53 +0100
commit8e82785c584dc13e20f9229decb95bd17bbe9cd1 (patch)
treea8b359e59196be5b2e3862bed189107f4bc9975f /src/core/gpio.c
parentMerge branch 'master' into openslx (diff)
parent[prefix] Make unlzma.S compatible with 386 class CPUs (diff)
downloadipxe-openslx.tar.gz
ipxe-openslx.tar.xz
ipxe-openslx.zip
Merge branch 'master' into openslxopenslx
Diffstat (limited to 'src/core/gpio.c')
-rw-r--r--src/core/gpio.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/src/core/gpio.c b/src/core/gpio.c
new file mode 100644
index 000000000..f57139a11
--- /dev/null
+++ b/src/core/gpio.c
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdlib.h>
+#include <errno.h>
+#include <ipxe/gpio.h>
+
+/** @file
+ *
+ * General purpose I/O
+ *
+ */
+
+/** List of GPIO controllers */
+static LIST_HEAD ( all_gpios );
+
+/**
+ * Allocate GPIO controller
+ *
+ * @v count Number of GPIO pins
+ * @v priv_len Size of driver-private data
+ * @ret gpios GPIO controller, or NULL
+ */
+struct gpios * alloc_gpios ( unsigned int count, size_t priv_len ) {
+ struct gpios *gpios;
+ struct gpio *gpio;
+ size_t len;
+ unsigned int i;
+
+ /* Allocate and initialise structure */
+ len = ( sizeof ( *gpios ) + ( count * sizeof ( *gpio ) ) + priv_len );
+ gpios = zalloc ( len );
+ if ( ! gpios )
+ return NULL;
+ gpios->count = count;
+ gpios->gpio = ( ( ( void * ) gpios ) + sizeof ( *gpios ) );
+ gpios->priv = ( ( ( void * ) gpios ) + sizeof ( *gpios ) +
+ ( count * sizeof ( *gpio ) ) );
+
+ /* Initialise GPIO pins */
+ for ( i = 0 ; i < count ; i++ ) {
+ gpio = &gpios->gpio[i];
+ gpio->gpios = gpios;
+ gpio->index = i;
+ }
+
+ return gpios;
+}
+
+/**
+ * Register GPIO controller
+ *
+ * @v gpios GPIO controller
+ * @ret rc Return status code
+ */
+int gpios_register ( struct gpios *gpios ) {
+
+ /* Add to list of GPIO controllers */
+ gpios_get ( gpios );
+ list_add_tail ( &gpios->list, &all_gpios );
+ DBGC ( gpios, "GPIO %s registered with %d GPIOs\n",
+ gpios->dev->name, gpios->count );
+
+ return 0;
+}
+
+/**
+ * Unregister GPIO controller
+ *
+ * @v gpios GPIO controller
+ */
+void gpios_unregister ( struct gpios *gpios ) {
+
+ /* Remove from list of GPIO controllers */
+ DBGC ( gpios, "GPIO %s unregistered\n", gpios->dev->name );
+ list_del ( &gpios->list );
+ gpios_put ( gpios );
+}
+
+/**
+ * Find GPIO controller
+ *
+ * @v bus_type Bus type
+ * @v location Bus location
+ * @ret gpios GPIO controller, or NULL
+ */
+struct gpios * gpios_find ( unsigned int bus_type, unsigned int location ) {
+ struct gpios *gpios;
+
+ /* Scan through list of registered GPIO controllers */
+ list_for_each_entry ( gpios, &all_gpios, list ) {
+ if ( ( gpios->dev->desc.bus_type == bus_type ) &&
+ ( gpios->dev->desc.location == location ) )
+ return gpios;
+ }
+
+ return NULL;
+}
+
+/**
+ * Get null GPIO input value
+ *
+ * @v gpios GPIO controller
+ * @v gpio GPIO pin
+ * @ret active Pin is in the active state
+ */
+static int null_gpio_in ( struct gpios *gpios __unused,
+ struct gpio *gpio __unused ) {
+ return 0;
+}
+
+/**
+ * Set null GPIO output value
+ *
+ * @v gpios GPIO controller
+ * @v gpio GPIO pin
+ * @v active Set pin to active state
+ */
+static void null_gpio_out ( struct gpios *gpios __unused,
+ struct gpio *gpio __unused, int active __unused ) {
+ /* Nothing to do */
+}
+
+/**
+ * Configure null GPIO pin
+ *
+ * @v gpios GPIO controller
+ * @v gpio GPIO pin
+ * @v config Configuration
+ * @ret rc Return status code
+ */
+static int null_gpio_config ( struct gpios *gpios __unused,
+ struct gpio *gpio __unused,
+ unsigned int config __unused ) {
+ return -ENODEV;
+}
+
+/** Null GPIO operations */
+struct gpio_operations null_gpio_operations = {
+ .in = null_gpio_in,
+ .out = null_gpio_out,
+ .config = null_gpio_config,
+};